ST. HELENS, Ore. – So far as she knows, Pufferbelly Toys owner Stephanie Cox hasn’t been passing any state secrets to sinister foreign governments, or violating obscure clauses in the Patriot Act.

So she was taken aback by a mysterious phone call from the U.S. Department of Homeland Security to her small store in this quiet Columbia River town just north of Portland.

“I was shaking in my shoes,” Cox said of the September phone call. “My first thought was the government can shut your business down on a whim, in my opinion. If I’m closed even for a day that would cause undue stress.”

When the two agents arrived at the store, the lead agent asked Cox whether she carried a toy called the Magic Cube, which he said was an illegal copy of the Rubik’s Cube, one of the most popular toys of all time.

He told her to remove the Magic Cube from her shelves, and he watched to make sure she complied.

After the agents left, Cox called the manufacturer of the Magic Cube, the Toysmith Group, which is based in Auburn, Wash. A representative told her that Rubik’s Cube patent had expired, and the Magic Cube did not infringe on the rival toy’s trademark.

Virginia Kice, a spokeswoman for Immigration and Customs Enforcement, said agents went to Pufferbelly based on a trademark infringement complaint filed in the agency’s intellectual property rights center in Washington, D.C.

“One of the things that our agency’s responsible for doing is protecting the integrity of the economy and our nation’s financial systems and obviously trademark infringement does have significant economic implications,” she said.

Six weeks after her brush with Homeland Security, Cox told The Oregonian she is still bewildered by the experience.